Hello,
i’m currently find a way to open a modal window(at the moment i would use one provided at starting point ex: ListColumsChooser or anything else) from my custom listview action button.
Creating Custom Action Button -> no problem
Adding code to launch a modal -> need help
That Javascript part invoking the Yahoo libraries (YUI).
See if you can make anything from it, but it is not the best example since the logic of sending stuff from backend to frontend, etc, can be a bit confusing.